Effects of Different Irrigation Amounts on Water Use of Precocious Walnuts

2014 ◽  
Vol 651-653 ◽  
pp. 1423-1431
Author(s):  
Hua Bing Ma ◽  
Mei Mei Li ◽  
Jun Jie Ren ◽  
Bao Guo Li ◽  
Guo Hui Qi
Keyword(s):  
Diurnal Variation ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Soil Water ◽  
Water Use ◽  
Leaf Water Potential ◽  
Sap Flow ◽  
Leaf Water ◽  
Flow Rates ◽  
Use Efficiency

Objective : To provide scientific guidance for water management of precocious walnuts. Method: With 8 years old ‘Lvling’ walnut trees as samples, 5 irrigation quantity treatments were designed, including 0, 15, 30, 45 and 60 kg of water per plant for each time, respectively and the routine irrigation amount (CK) was 600 kg of water per plant for each time. During the draught stage in growing season, 3 times of irrigation were carried out, and the effects of different treatments on sap flow, water use efficiency, yield and fruit quality were compared. Results: The daily instantaneous maximum average sap flow rates were found with 60 kg of water and control; the daily highest average water use efficiency was 1.54 mmol/mol with the treatment of 30 kg water; the daily highest average leaf water potential was-1.23 MPa with control; the highest yield per plant (1.48 kg) was found with the control, and the yield of 45 kg and 60 kg water per plant one time accounted for 98.65% and 99.32% of that of control, respectively. with T1 the yield was the lowest, only accounting for 70.65% of the control. Conclusion: As the soil water contents increased, the diurnal variation curve of sap flow rates changed from unimodal to bimodal patterns in sunny days, the main peak was narrowed; the curve of diurnal variation of leaf water potential changed from "V" to "W" type; the leaf water use efficiency increased initially and then decreased later; and the nut quality was improved and the yield increased. The optimal soil water content (SWC) of 'Lvling' precocious walnuts ranged from 20.01% ~ 21.96%.

scholarly journals Impact of Kaolin Particle Film and Water Deficit on Wine Grape Water Use Efficiency and Plant Water Relations

HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1178-1187 ◽  
Author(s):  
D. Michael Glenn ◽  
Nicola Cooley ◽  
Rob Walker ◽  
Peter Clingeleffer ◽  
Krista Shellie
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stomatal Closure ◽  
Canopy Temperature ◽  
Leaf Water ◽  
Film Treatment ◽  
Use Efficiency ◽  
Moisture Conditions

Water use efficiency (WUE) and response of grape vines (Vitis vinifera L. cvs. ‘Cabernet Sauvignon’, ‘Merlot’, and ‘Viognier’) to a particle film treatment (PFT) under varying levels of applied water were evaluated in Victoria, Australia, and southwestern Idaho. Vines that received the least amount of water had the warmest canopy or leaf surface temperature and the lowest (more negative) leaf water potential, stomatal conductance (gS), transpiration (E), and photosynthesis (A). Vines with plus-PFT had cooler leaf and canopy temperature than non-PFT vines; however, temperature difference resulting from irrigation was greater than that resulting from PFT. In well-watered vines, particle film application increased leaf water potential and lowered gS. Point-in-time measurements of WUE (A/E) and gS did not consistently correspond with seasonal estimates of WUE based on carbon isotope discrimination of leaf or shoot tissue. The response of vines with particle film to undergo stomatal closure and increase leaf water potential conserved water and enhanced WUE under non-limiting soil moisture conditions and the magnitude of response differed according to cultivar.

Water uptake depth is coordinated with leaf water potential, water‐use efficiency and drought vulnerability in karst vegetation

2020 ◽  
Vol 229 (3) ◽  
pp. 1339-1353
Author(s):  
Yali Ding ◽  
Yunpeng Nie ◽  
Hongsong Chen ◽  
Kelin Wang ◽  
José I. Querejeta
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Water Uptake ◽  
Leaf Water Potential ◽  
Leaf Water ◽  
Drought Vulnerability ◽  
Use Efficiency

Vertical Wilting and Photosynthesis, Transpiration, and Water Use Efficiency of Sunflower Leaves

1979 ◽  
Vol 6 (1) ◽  
pp. 109 ◽  
Author(s):  
HM Rawson
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Stomatal Closure ◽  
Net Photosynthesis ◽  
Leaf Water ◽  
Vertical Orientation ◽  
Use Efficiency ◽  
Node Position

Plants of two sunflower cultivars were exposed to a number of soil drying cycles and the gas exchange of young, fully expanded leaves at different nodes was measured continuously from when the leaves were turgid until when they were severely and vertically wilted. Peak rates of net photosynthesis increased with the height of leaf insertion but, regardless of node position, leaves at vertical wilting always had rates of net photosynthesis which were close to 50% of peak rates. Although the leaf water potential at which vertical wilting occurred ranged between - 1.3 and -2.2 MPa and varied even for a particular leaf position, there was a similar relationship between the rate of reduction in photosynthesis and the reduction in leaf water potential. No evidence was found for a threshold leaf water potential at which stomatal closure occurs. Water use efficiency improved when leaves changed from a horizontal to a vertical orientation, apparently through changes in leaf temperature but. by the stage of wilting, water use efficiency had already markedly improved over efficiencies of turgid leaves. Much of this improvement stemmed from changes in leaf conductances. No clear differences between cultivars were evident in any parameter measured. The likely effects that wilting will have on water use efficiency in the field and strategies for optimising water use on a diurnal basis are discussed.

Agronomic and Physiological Responses of Soybean and Sorghum Crops to Water Deficits. IV. Photosynthesis, Transpiration and Water Use Efficiency in Leaves

1978 ◽  
Vol 5 (2) ◽  
pp. 195 ◽  
Author(s):  
HM Rawson ◽  
NC Turner ◽  
JE Begg
Keyword(s):  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Flag Leaf ◽  
Grain Filling ◽  
Leaf Water ◽  
Water Deficits ◽  
Use Efficiency ◽  
Soybean Leaves

Detailed diurnal measurements of photosynthesis, transpiration and water use efficiency of leaves of sorghum and soybean were made during the reproductive growth of field plants. Photosynthesis was measured mainly by infrared gas techniques. The indication in well watered plants was that diurnal net carbon fixation per unit area of sorghum leaves was some 2.3 times greater than that of comparably illuminated soybean leaves while concurrent transpiration losses were less. Simple carbon budgets for the two crops over 24 h suggested that the assimilation by a leaf area equivalent to that of the flag leaf was required solely to sustain respiration by the sorghum head during mid- grain filling, while approximately 5 cm� of leaf was required to sustain respiration of each soybean pod. The comparisons made on a diurnal basis between plants of soybean exposed to different water deficits during grain filling demonstrated the increasing importance of early morning and late afternoon photosynthesis as water became less available. They also showed the rapidity with which plants can recover from stress once water is supplied. It is calculated that, for continuously clear conditions, as daily minimum leaf water potential fell from - 1 .5 to - 2.5 MPa, the integrated daily assimilation by leaves was reduced by about 9 % for every 0.1 MPa change; soybean leaves were not measured at leaf water potentials much below - 2.6 MPa. A ratio between gas phase and residual resistances remained relatively stable over the range of leaf water potential measured. However, the water use efficiency of single leaves was reduced with increasing soil water deficits because of changes in leaf temperature and leaf-to-air vapour pressure differences.

Effects of No-tillage and Ploughing on Efficiency of Water Use in Maize and Cowpea

1978 ◽  
Vol 14 (2) ◽  
pp. 113-119 ◽  
Author(s):  
R. Lal ◽  
P. R. Maurya ◽  
S. Osei-Yeboah
Keyword(s):  
Zea Mays ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Vigna Unguiculata ◽  
Sprinkler System ◽  
Leaf Water ◽  
No Tillage ◽  
Use Efficiency

SUMMARYWater use efficiency of maize (Zea mays) and cowpea (Vigna unguiculata) was investigated, with and without tillage, under four irrigation frequencies in which 12 mm of water was applied at 2, 4, 8 and 12 day intervals, using a sprinkler system. Both maize and cowpea under no-tillage yielded more than with conventional ploughing. Water use efficiency of maize without tillage was 18·3, 17·5, 57·8 and 100% greater than with tillage at irrigation frequencies of 2, 4, 8 and 12 days respectively. Whereas the leaf water potential of cowpea was not affected by tillage, that of maize was generally higher for no-tillage compared with conventional ploughing.

Hydraulic limitations and water-use efficiency in Pinus pinaster along a chronosequence

2008 ◽  
Vol 38 (1) ◽  
pp. 73-81 ◽  
Author(s):  
Federico Magnani ◽  
Abdelkader Bensada ◽  
Sergio Cinnirella ◽  
Francesco Ripullone ◽  
Marco Borghetti
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Pinus Pinaster ◽  
Hydraulic Conductance ◽  
Leaf Water ◽  
Stand Development ◽  
Use Efficiency

Hydraulic constraints to water transport and water-use efficiency were studied in a Pinus pinaster Ait. chronosequence in Italy, consisting of four even-aged stands ranging from young (10 years old) to mature (75 years old), to explore the mechanisms involved in the decline of stand productivity as tree grow taller. Leaf-specific transpiration was estimated from sapflow rates measured by the heat dissipation technique, leaf-specific hydraulic conductance was computed from the slope of the relationship between transpiration and leaf water potential, long-term water-use efficiency was estimated from carbon isotope discrimination (Δ13C) in xylem cores, and photosynthetic capacity was assessed from CO2 assimilation/CO2 intercellular concentration curves. Leaf-specific transpiration decreased with stand development, suggesting a reduction in stomatal conductance, and a negative relationship was found between leaf-specific hydraulic conductance and tree height, suggesting a role of hydraulic constraints in the decline of current annual increment. Minimum daily leaf water potential did not change with stand height, suggesting that homeostasis in leaf water potential is achieved through a reduction in leaf transpiration. The Δ13C values increased with stand development, indicating a decline of water-use efficiency. Leaf level stomatal conductance was higher in the younger stand; no significant difference in maximum carboxylation rate was found among stands.

Partial rootzone drying increases water-use efficiency of lemon Fino 49 trees independently of root-to-shoot ABA signalling

2012 ◽  
Vol 39 (5) ◽  
pp. 366 ◽  
Author(s):  
J. G. Pérez-Pérez ◽  
I. C. Dodd ◽  
P. Botía
Keyword(s):  
Stomatal Conductance ◽  
Water Use Efficiency ◽  
Water Potential ◽  
Water Use ◽  
Leaf Water Potential ◽  
Vapour Pressure ◽  
Vapour Pressure Deficit ◽  
Leaf Water ◽  
Use Efficiency ◽  
Partial Rootzone Drying

To determine whether irrigation strategy altered the sensitivity of Citrus leaf gas exchange to soil, plant and atmospheric variables, mature (16-year-old) Fino 49 lemon trees (Citrus limon (L.) Burm. fil. grafted on Citrus macrophylla Wester) were exposed to three irrigation treatments: control (irrigated with 100% of crop potential evapotranspiration, ETc), deficit irrigation (DI) and partial rootzone drying (PRD) treatments,which received 75% ETc during the period of highest evaporative demand and 50% ETc otherwise. Furthermore, to assess the physiological significance of root-to-shoot ABA signalling, the seasonal dynamics of leaf xylem ABA concentration ([X-ABA]leaf) were evaluated over two soil wetting–drying cycles during a 2-week period in summer. Although stomatal conductance (gs) declined with increased leaf-to-air vapour pressure deficit (LAVPD), lower leaf water potential and soil water availability, [X-ABA]leaf was only related to stomatal closure in well irrigated trees under moderate (<2.5 kPa) atmospheric vapour pressure deficit (VPD). Differences in [X-ABA]leaf were not detected between treatments either before or immediately after (<12 h) rewatering the dry side of PRD trees. Leaf water potential was higher in control trees, but decreased similarly in all irrigation treatments as daily LAVPD increased. In contrast, DI and PRD trees showed lower stomatal sensitivity to LAVPD than control trees. Although DI and PRD decreased stomatal conductance and photosynthesis, these treatments did not significantly decrease yield, but PRD increased crop water use efficiency (WUE) by 83% compared with control trees. Thus PRD-induced enhancement of crop WUE in a semiarid environment seems to involve physiological mechanisms other than increased [X-ABA]leaf.

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